For nearly 500 years, the Vikings lived and thrived in Greenland. Taking advantage of the Medieval Warm Period, they established outposts in the North Atlantic where they farmed and ranched. But quite suddenly, at the mid-point of the 15th century, they abandoned their settlements and ventured back to Scandinavia. Anthropologists have theorized that they were responding to massive crop failures caused by changing climate conditions, but a new paper published in the Journal of the North Atlantic suggests that this is entirely wrong, and that there were other reasons for the sudden change of heart.

Starting at the end of the 10th century, Vikings established hundreds of scattered farms along protected fjords, where they built their homes and churches. Life was good living alongside the edge of the glaciers, but by the 15th century the conditions had cooled dramatically, putting an abrupt end to their farming lifestyle. It's this change, say anthropologists, that caused extensive crop failure and starvation — forcing them to return back to Europe.

But as new research from a Danish-Canadian team now shows, this couldn't possibly have been the case.

According to Jan Heinemeier, Niels Lynnerup, and Jette Arneborg, extensive evidence of the Vikings' dietary habits indicate that they adapted quite well to the changing conditions, becoming fishermen and seal hunters. And in fact, up to 80 percent of their diet consisted of seal meat by the 14th century. In a sense, they were becoming more like the Inuit, and less like Vikings.

So, if it wasn't starvation or disease, what triggered the abandonment of the Greenland settlements in the second half of the 15th century? The scientists suspect that a combination of causes made life there unbearable for the Scandinavian immigrants. For instance, there was hardly any demand anymore for walrus tusks and seal pelts, the colony's most important export items. What's more, by the mid-14th century, regular ship traffic with Norway and Iceland had ceased.

As a result, Greenland's residents were increasingly isolated from their mother countries. Although they urgently needed building lumber and iron tools, they could now only get their hands on them sporadically. "It became more and more difficult for the Greenlanders to attract merchants from Europe to the island," speculates Jette Arneborg, an archeologist at the National Museum of Denmark, in Copenhagen. "But, without trade, they couldn't survive in the long run."

The settlers were probably also worried about the increasing loss of their Scandinavian identity. They saw themselves as farmers and ranchers rather than fishermen and hunters. Their social status depended on the land and livestock they owned, but it was precisely these things that could no longer help them produce what they needed to survive.

Moreover, the Vikings abandoned Greenland in an orderly manner. There was no panic to leave — another sign that they gradually realized that it was time to head back home.